Rotary compressor



Feb. 1 1927.

E. C. BELL ROTARY COMPRESSOR -2 Sheets-Sheet 1 Filed Feb. .5, 1924 7 96 x g F ,mq v w i I 4 I UK //C/ mm Feb 1 s 1927' F. c. BELL I ROTARY COMPRESSOR Fil ed Feb. 5, 1924 2 Sheets-Sheet 2 If I FRED C.BELL.

E MA; v

Patented Fa. 1,1927. c I 1,615,824

UNITED STATES PATENT OFFICE. I I men 0. mm, or stamens, cnmroimra. i

v I ROTARY eomranssoa.- Application filed February -5,'1a24 "swarm. 690,759.

This invention relates to a compressor of or contact therewith continuously during opthe rotary vane type, and especially to a eratlon of therotor. compressor of this character which is The rotor is driven by means of a mm or ada ted to handle such gases as sulphur didriving'shaft such as indicated at 15. This oxi e, etc. when employed in small refrigershaft extends through the stuffing box 4 and ating plants. may be direct connected to an electric motor v The object of the present invention is to or other suitable driving means. The mner generally improve and simplify the conend of the shaft 15 is prov1ded 'w1th a couostruction and operation of compressors of ling and a driving connectlon 1s thus 10 the character described, and further to proormed between the shafts lland '15.

Vide a structure which ermits eflicient lubri- The cylinder is provided with two inlet cation and cooling 015516 compressor. ports such as indicated at 16 and ,17, and .65

One form which my invention may assume with a single discharge port as indlcated at is exemplified in the following description 18. The inlet port 16 is extended through 1 and illustrated in the accompanying drawone side of the cylinder and passes through 'in s, inwhichthe intermediate head at the point indicated i 1 is a diagrammatic view showing at 16. It here communicates with a port one orm of refrigerating plant or system 16 formed in the headmember 2, this port in which the compressor may be employed. being connected with the discharge side of I 20 Fig. 2 is a central, vertical, longitudinal an expansion or cooling coil hereinafter to be section of the compressor. referred to. The port 17, which is also Fig. 3 is a cross-section on line 3-3, Fig. 2. an inlet port and which delivers the lubri- Referring to the drawings in detail, and cant to the cylinder, extends. through the particularly to Figs. 2 and 3, A indicates a o posite side of the cylinder and passes base member on which is formed a circular tliiough communicating ports 17 and 17 ordisk shaped head 2.. Forming an exten= formed in the outer head 7 and in the cover sion thereof is a bearing member 3, and plate 8. A vertically disposed pipe 18 is 90 mounted in the outer end thereof is a stufiing connected with the port 17 and lubricant box 4. Mounted on .the face of the head is delivered to the upper end of this pipe 30 member 2 is ,an inner cylinder head 5, and as will hereinafter be described. The cylinsecured to said head are a cylinder 6, an der 6, together with the head members 5' and outer cylinder head 7, and a cover plate 8;..7, and the cover plate 8, is entirely enclosed the members 5, 6, 7 and 8 beingsecured to by an exterior cap creasing generally inthe main head 2 by means of bolts 9. dicated at 19. This casing is flanged and is Mounted in the intermediate heads5 and 7 bolted to the main head member 2 as indiare anti-friction bearings 10, and journalled cated at 20. An annular space 21 is formed in-s'aid bearings is a shaft 11 on which is sebetween the compressor unit and the exterior cured a rotor 12. casing 19 and an end space is also formed The rotor proper is slotted from endto as "indicated at 22 to form sufficient room 40 end as indicated at 13, and each slot serves for the lubricating pipe 18; The annular as a guide and carrier for a vane 14. There space 21, together wlth the end space 22, is are four slots and vanes employed in the. filled with oil and this oil is delivered to present instance but the number may be inthe upper portion of the annular space by creased if desired as this does not forman a port 23, the opposite end of which comimportant feature of the present invention. municate's with an annular space 24 formed The cylinder 6 is eccentrically positioned exterior of the stuffing gland, oil being in s with relation to the rotor 12 and the shaft turn delivered to the jacket or space 24 by 11 and as the vanes are free to move in the means of a pipe 25 which is connected with slots '13 reciprocal movement will be ima'combination condenser and oil cooler hereparted to the vanes during rotationof the inafter to be referredto, rotor; that is, the vanes will be restricted The compressor here illustrated is ar-.

in their outward movement by the. inner ticularly designed for use in small re igface of the cylinder and as'such will follow crating plants employing sulphur. dioxide or like refrigerating medium, and for the purpose of describing its function and operation reference will be made to Fig. 1, which a. 7 18 a diagrammatic view showing one form of refrigerating plant in which it may be employed. Tn this plant A. indicates the w through a pipe 26 with the discharge side of the cooling or expansion coil C, while the opposite side of the coil is connected through a pipe 27 with the expansion valve D. This valve in turn communicates with the lower end of the combination condenser and oil separator as shown- The other inlet port, through which the lubricant is admitted and which is indicated at 17, is connected by means of the pipe with a vertical standpi e 28 which enters the lower end of the condenser and cooler indicated at E. It extends a suiiicient distance. up-

: wardly into this cooler'to communicate with livered to the upper end dioxide,

an oil stratum formed therein and lubricas ting oil in a fairly purestate is delivered thereto.

The discharge port of the compressor, indicated' at 18, is connected with the combination condenser and cooler by means of a pipe 29 and a continuous cycle of circulation is thus permitted.

In actual practice when the compressor is in operation expanded gases are delivered to the suction side of the compressor through the pipe 26. This gas is compressed and is heated by the compressing action and is discharged through the pipe 29 and deof the combined condenser and oil separator. The hot ases entering are mixed with, oil, .as will Tiereinafter be described, and'the gases under compression, together with any oil vapors contained, will here be condensed as a cooling medium through a condensing coil such as indicated at 30. The refrigerant, for instance sulphur when liquefied or condensed is considerably heavier than the oil and they will therefore collect and separate and furthermore stratify in the lower portion of the combined condenser and oil separator, the liquefied sulphur dioxide beingindicated at 31 and the oil at 32 The discharge pressure of the compressor is maintained inthe condenser and oil separator as pipe '29 is in direct communication therewith and .oil and liquefied sulphur charged-under pressure. p The liquefied sulphur dioxide is discharged through the expansion valve D and is thus permitted expand and assume a lower temperature denser, cooler and separator,

is continuously circulateddioxide will thus be disto. I

the compressor,

' aeiaeaa when passing through the pipe cooling or. expansion coil C; the gases after completing their useful cycle being again returned to the compressor through the pipe 26. The oil is discharged through the standpipe 28 under the same pressure as the liquefied sulphur dioxide and enters the jacket of the stuffing gland t through the pipe It is here circulated around the gland in the jacket space 2 2 and then passes upwardly through the port 23 from where it discharges into the annular chamber 21 and the end passage 22. The oil then cir culates around the compressing unit proper and when so circulating performs two functions, first that of coolin the heated compression or discharge si e of the cylinder, and secondly that of warming the cold inlet or suction side of the cylinder; that is, returning gases from usually very cold, and it is for this reason that one side of the cylinder is cold and the other warm from compression. The circulation of oil around the cylinder tends to promote a uniform temperature in the coinpressor cylinder and as such obviates unequal expansion thereof.

The oil after performing its function of 2? and the the lubricating pipe 18 which communicates with the inlet port 17 of the compressor. It here serves three functions, first that of lubricating and packing the compressor, secondly that of increasing directly absorbing heat or compression during the compression cycle. mitted is swept or forced out'through the discharge port 18 together with the compressed gases, and thus enters the pipe 29 which again returns the hot compressed gases and the oil to thus completwhich is repeated long as the coming the cycle of operation over and over again as pressor is in operation.

By referring to Fig. 3 it will be noted that the inlet ports 16 and 17 are, practically speaking, positioned diametrically opposite to each other. This is important as it first of all ermits each vane to sweep around and in uce a complete charge of gas. charge of gas is pocketed or trapped between two' sets of vanes and lubricating 'oil is not delivered thereto until this trap or pocket has been completely filled. The complete' filling of the pocket has taken place by the time the foremost vane of the pocket passes the lubricating port 17, and as the gas at this point is substantially atmospheric or perhaps'sliglhtly under atmospheric (pressure and as t e oil is r'naintainedun er a pressure equal to the discharge pressure of it is obvious that the oil will the efficiency of the compression cycle, andthird that of the combination con- The oil thus adenter the pocket freely and will continue entering until the pressure of the gas and oil step of the compression cycle. Further rotation of the vanes will cause the size'of the pocket with entrapped gas and oil to be reduced in cubic .capacit' due to the eccentric position of the cylinder, and the as 1scharged with the oi through the port 18.

will thus be fin'all compressed .and

By admitting the oil under pressure and at the point desired, the eapacit of the compressor is not interfered wit as a full charge of gas is admitted before the lubricant. The lubricant when admitted serves to partially compress this gas, and it may furthermore be stated that as the lubricant is not admitted until the compression cycle starts, it is obvious that it is applied at the proper time Where it will render the best effeet, as far as lubrication is concerned, as it is only during the compression cycle that leakage to any extent is liable to occur, but as the compressor is liberally supplied With lubricant at this point leakage is, as a consequence, reduced to a minimum. Again, by injecting cold oil just at the time the compressor is filled with low pressure gas, the amount ,ofinjected oil need not be restricted or in any way regulated as the gradual compression'of the-gas trapped between the vanes will automatically serve to restrict the quantity of oil admitted. The oil thus admitted also serves the function of absorbing a large proportion of the heat generated in the gas during the cycle of compression and as oil is a better conductor of heat than as, it is obvious that the area of the conenser or cooler and the-amount of c1rculat ing water required may be reduced.

The cooling of the cylinder unit and the stufling box with oil is also ,an important factor as leakage, if any, would have no serious consequence. If water were" circulated and leakage should take place, acid might be formed, particularly where sulphur dioxide is employed and corrosion would rapidly take place, This, (1 er; is, however, entirely eliminated by emp oymg the lubricating oil for this purpose.

v The arrangement of the port 23 and th oil lips 18 is also important, that is, they both communicate with the highest points in the respective jackets, thus avoiding the formation of gas traps or pockets which might interfere with .cooling and circulation of'the oil. i

While certain features of the'present in vention are more or less specifically illustrated, I wish it understood that various changes in form andproportion maybe resorted to within the scope of the-appended claims. I similarly wish it understood that the materials and finish of the several parts employed may be such as the experience and judgment of the manufacturer may'dictate or varioususes may demand.

Having thus described my invention, "what I -claim and desire to secure by Letters Patent is- 1. A compressor of the character described comprising a main supporting late, a rotary compressor. supported there y, a driving shaft extending through the supporting plate to drive the compressor, a

cup-shaped casing secured to the supporting plate and enclosing the rotary compressor, said cup-shaped casing bein spaced therefrom to form an intermediate chamber,

-means for delivering oil under pressure to said intermediate chamber, and means for transferring the oil from said intermediate chamber to the compression side of the rotary compressor.-

2. A compressor of the character doscribed, comprising a main supporting plate a cover plate, a pair of cylinder heads an an interposed cylinder secured thereto, a shaft journalled in the cylinder heads and extending through the cylinder, a rotor secured to the shaft and provided with a pluralit of reciprocally mounted, radially dispose vanes, said rotor and-shaft being cylinder, a cup shaped casing enclosing the I it to the compression'side of the cylinder, 4

and. means communicating with the c linder for the admission andexplusion of uid to be compressed, v i

3. A compressor of the character described, comprising a main supporting plate, a cover plate, apair of cylinder heads and an interposed cylinder secured thereto, a

shaft journalled in the cylinder heads and extending throu' h the cylinder, a rotor secured to the siaft and provided with a plurality of reciprocally mounted, radially disposed vanes, said rotor and shaft being eccentrically positioned with relationto the cylinder, cover plate, the

therefrom to an intermediate chamber,

said cup shaped casing being secured to' the supporting plate, a stu'fling box formed on the supporting plate through which the rotor shaft extends, '.'a jacket formed ex terior thereof, means fordelivering oil under .pressure to saidjacket, means for conveying the oil from the jacket to the annular-space formed within the cup shaped casing to permit the oil, to circulate around andcooh .a cup shaped casin enclosing the c lmder hea sand the cyl-- tinder, said cufp orm 05 eccentrically positioned with relation to the aped casing being p d J20 tioned on opposite sides of t the cylinder, means for conveying the oil from said annular space to the cylinder and for delivering the oil into the cylinder on the side where, compression takes place, means for deliverin the fluidto be. compressed to the cylin er and common means for receiving the oil delivered to the cylinder and the compressed fluid. v

4. A compressor of the character described comprising a main supporting plate, a rotary compressor supported thereby, a shaft extending through the supporting plate and connected with the compressor to drive the same, a cup-shaped casing secured to the supporting plate and enclosing the rotary compressor, said cup-shaped casing being spaced therefrom to form an internrediate chamber, means for delivering oil under pressure to said chamber, said compressor having oil inlet ports formed therein in communication with the compression side thereof, and means for conveying oil from the uppermost ortion of the intermediate chamber to said oil inlet ports.

5. A compressor of the character described, comprising a cylinder, an inner and an outer cylinder head mounted at each end thereof, a shaft journalled in the cylinder heads and extending through the cylinder and through the inner head,-said shaft being eccentrically positioned with relation to the cylinder, a rotor secured to the shaft within the cylinder," said rotor being provided with radially disposed, reciprocally mounted vanes, said cylinder being provided "with an inlet and a discharge port posie rotor, and said cylinder being further provided with an oil inlet port, said tioned on the side of the cylinder where compression takes place, a support-ing plate to which the c linder is secured, saidsupporting plate iavin inlet and discharge ports formed therein in communication with the cylinder inlet and discharge ports, a cup shaped casing secured to the supporting late and encloslngthe cylinder, said cas-.

mg being spaced from the cylinder to form an oilcirculating and cooling chamber, a jacketed stufiing box formed on the supporting plate through which the rotor shaft extends, means for delivering oil under pressure to said jacketed stufiing box means for conveying the oil from said jacket to'the oil circulating and cooling chamber, and means for conve ing the oil from said chamber to he oil in ct port of the cylinder. 6 A compressor of the character described, comprising a cylinder, an inner and an outer cylinder head mounted at each end thereof. ashaft journalled in the cylindcr heads and extending through thecylinder and through the innerhead, said shaft being eccentrically positioned with relation to the cylinder, a rotor secured to the shaft .veying the oil from circulating and cooling chamber, and means inlet port being posi- 1,e1s,as4 v a within the cylinder, said rotor being provided with radially disposed, reciprocally mounted vanes, said cylinder being provided with an inlet and a discharge port positioned on opposite sides of the-rotor, and said cylinder being further provided with an oil inlet port, said inlet port being positioned on the .side of the cylinder where compression takes place, a supporting plate to which the cylinder is secured, said supporting plate having inlet and discharge ports formed therein in communication with the cylinder inlet and discharge ports, a cup shaped casing secured to the supporting plate and enclosing the cylinder, said casing being spaced from the cylinder to form an oil circulating and cooling chamber, a jacketed stufiing box formed on the supporting plate means for delivering oil under pressure to said jacketed stufling box, means for consaid iacket to the oil for conveying the oil from said chamber to the oil inlet port of the cvlinder, said means comprising a vertical standpipe communicating at its upper end with the upper portion of said chamber, and at its lower end with the oil inlet port of the cylinder.

7 A compressor of the character described comprising a main supporting plate, a rotary compressor supported thereby, a shaft extending through the supporting plate and connected with the compressor to drive the same, a cup-shaped casing secured to the supporting plate and enclosing the rotary compressor, said cup-shaped caslng being spaced therefrom to form an intermediate chamber, means for delivering oil under pressure to said chamber, said compressor having oil inlet ports formed therein in communication thereof, and a pipe connected ports at one end, the other end of terminating in the uppermost portionp the intermediate chamber, said pipe forming a fluid duct for the oil under pressure and also preventing the formation of a gas pocket in the upper portion of the intermediate chamber.

8. A compressor of the character de scribed comprising a main supporting late, a rotary compressor supported there y, a shaft extending through the supporting late through which the rotary (ompressor is driven, a stufiing box on the supporting plate through which said shaft extends. a jacket exte'riorly of said st-ufiing box, a cup.-

with said inlet said pipe shaped casing secured to the supporting fromto form an intermediate chamber, f

means for delivering oil under pressure to the stuiling box jacket, means for transferring the oil from said jacket to the intermewith the compression side f in digjse space between the cup-shaped casing and the compressor, and means for transferring the oil from said intermediate space to the compression side ofthe rotary compressor; v V

9. The combination with a compressor of the character described, of a cup-shaped casing enclosing the compressor, a plate supportin the compressor. and also the cup shape housing, said cup shaped casing being spaced from the compressor to form an intermediate chamber, a stuffing box formed on' the supporting plate through which a shaft in the compressor extends; a.

jacket formed exteriorly of the stufling box, means for delivering. oil under pressure to in the cup-shaped casing to permit the oil to circulate around the compressor and cool the same, and means for conveying the oil from said annular space into the cylinder and for delivering the oil on the side where compression takes place.- I

FRED-c. 

